Damping Off Of Seedlings

[jaideeguy]

Due to the rains and high humidity, I'm experiencing a lot of damping off of my recently started seedlings. Normally I just ride out this season and take a break from the garden, but this year, i'm going for it, but having problems from the start. Don't want to use fungicides, but will as a last resort.

Any organic alternatives????

Edited July 6, 2009 by jaideeguy

[loong]

I've hardly seen any rain so far, had a fair downpour yesterday and I was very happy to see it.

I've been working to form raised beds and better drainage for the wet season.

As I only have a small plot I start all my seedlings in black planting bags. That way I can make sure that they have very good drainage in a mixture of compost and rice husks. When they are strong enough, I transfer to the garden.

The hardest thing I find is to resist the temptation to separate the seedlings and transplant. This would damage the roots too much and not a good idea. If I have 5 seedlings growing in the one bag, I will discard 2 and plant the remaining 3 together. Later I will discard the 2 weakest.

[jaideeguy]

I've since googled 'damping off' and confirmed that it is a naturally occuring soil fungus, more prevelent in the wet/humid times and good air circulation as well as drier potting mix can reduce it. I can build a small well ventalated seed staring bench covered with plastic and sterilize my starting mix in small batches by steaming on the stove....but somewhat limited in containers and expect flack from the wife for dirtying up her kitchen and pots.

My rule of thumb is to go organic as long as it works, but when all else fails, I'll use light chems. Same same with my health. and in the seedling stage, any chems used in small amounts will be quite dilute by the time the plants are potted up and mature.

[jandtaa]

Hi Jaideeguy

Using a sterile seed starting base is an important step in preventing damping off. I also read in an article from the university of Ohio that adding 5% "hot compost" (from a recently heated pile) to your starting mixture will help as it is full of disease preventing beneficials.

When it's wet and humid make sure the surface is kept damp and not wet and give the seedlings as much light as possible.Consider using artificial light and maybe using a fan for improved air flow (using a wider spacing when sowing up trays will also help)

You could use a brew of chamomile tea (include some dried horsetail equisetum arvense for a really potent brew) if you can get hold of some. Water the starter trays with this brew before sowing and then spray the seedlings with it daily for a couple of weeks until the seedlings are past the vunerable stage. 

cheers for now

J

[jaideeguy]

OK, starting with sterilized soil makes good common sense. I have a rich potting mix of composted leaves, cow manuere, rice husks, klab and klab daam along with some of my clay soil, but it is not anywher near strerile [both with bacteria and seeds from grasses].

Trying to think of ways to sterilize larger amounts and what comes to mind would be to get a steel drum and fill it with soil and build a fire under it.

Any other ideas for a diy setup???

[jandtaa]

Hi JDG

I have been using my small electric oven for small amounts but am thinking of building a DIY contraption. Thinking of using steam injected through either some blue PVC or irrigation tubing with the soil sitting above on a fine mesh (old insect screen ??) so interested if you come up with something. I have a day off today so I might do a spot of googling and report back.

Also try searching in the farming forum for chitosan or red crab fertiliser there was a thread there. The liquid version is available fairly readily and although I'm not sure if it is effective against damping off the chitosan promotes general plant health and root production of seedlings so might be worth a try. In the UK I use this product

softguard

cheers for now J

[jandtaa]

Okay here's a couple of possibilities to work with

solar steriliser

let us know how you get on and post some pics if you knock something up.

Also google "chitosan damping off" loads of technical papers to wade through 

cheers for now J

soil_steriliser.pdf

[jaideeguy]

Looks like a cool [hot] idea, but the boiler pdf method seems costly and complicated for my small operation. The solar sounds cheap and easy to build....may try that or a version of it, but not much solar for the next few months.

Or may get a half 50gal drum and a smaller [30gal] durm to put inside it and fill with soil, then put some water in the 50gal drum and build a fire under to generate steam, or forget the steam and build a fire directly under the drum with soil.

Another project that will have to wait for now, but will get to it asap.